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71.
72.
Tatsuya Fukami Toshiyuki Yoshizato Shingo Miyamoto Hiroshi Yagi Fusanori Yotsumoto Kazuki Nabeshima Toru Hachisuga Masahide Kuroki Tatsuhiko Kawarabayashi 《Life sciences》2009,84(23-24):796-804
AimsThe aim of this study was to investigate the significance of epidermal growth factor receptor (EGFR) ligands produced in syncytiotrophoblasts during normal pregnancy.Main methodsWe examined the expression of EGFR ligands in human pregnancy by real-time PCR, and analyzed the relationship between EGFR ligands and human chorionic gonadotropin (hCG) or human placental lactogen in amniotic fluid by ELISA. In addition, we also examined the EGFR ligands in syncytiotrophoblasts and the amount of hCG secretion in JAR, JEG3 and BeWo cells in the presence of each EGFR ligand.Key findingsIn order to identify possible candidates among the EGFR ligands, we examined the predominant expression of an EGFR ligand in the chorionic villi and amniotic fluid during normal pregnancy, and analyzed the relationship between EGFR ligands and hCG in trophoblastic model cells. Amphiregulin was primarily expressed throughout human pregnancy and stimulated the secretion of hCG, indicating that amphiregulin is a key molecule among EGFR ligands.SignificanceAmphiregulin may play a pivotal role in the development or maturation of placenta. 相似文献
73.
74.
Kosuke Minamihata Masamichi Tokunaga Noriho Kamiya Shiro Kiyoyama Haruhiko Sakuraba Toshihisa Ohshima Masahiro Goto 《Biotechnology letters》2009,31(7):1037-1041
Peptide tags containing tyrosines (Y-tag) were introduced at the C-terminus of a hyperthermophilic enzyme, alkaline phosphatase from Pyrococcus furiosus (PfuAP). Immobilization of the recombinant PfuAPs onto water-in-oil-in-water (W/O/W) type microcapsules was performed by
an in situ polymerization method. All the recombinant PfuAPs prepared in this study were quantitatively immobilized onto microcapsules.
The PfuAP-immobilized microcapsules showed no significant loss of enzymatic activity until the 5th round of assays. This result
implies that the recombinant PfuAPs were covalently immobilized onto microcapsules. Immobilized PfuAP tagged with a Y-tag
having the sequence GGYYY exhibited approximately a twofold higher catalytic activity compared with the wild-type PfuAP.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
75.
Takashi Kitagawa Shingo Kimura Hideaki Nakata Harumi Yamada Akira Nitta Yoshikazu Sasai Hideharu Sasaki 《Environmental Biology of Fishes》2009,84(2):193-196
The habitat and movements of a Pacific bluefin tuna were investigated by reanalyzing archival tag data with sea surface temperature
data. During its trans-Pacific migration to the eastern Pacific, the fish took a direct path and primarily utilized waters,
in the Subarctic Frontal Zone (SFZ). Mean ambient temperature during the trans-Pacific migration was 14.5 ± 2.9 (°C ± SD),
which is significantly colder than the waters typically inhabited by bluefin tuna in their primary feeding grounds in the
western and eastern Pacific (17.6 ± 2.1). The fish moved rapidly through the colder water, and the heat produced during swimming
and the thermoconservation ability of bluefin tuna likely enabled it to migrate through the cold waters of the SFZ. 相似文献
76.
Atsushi Kameda Eugene‐Hayato Morita Kazumasa Sakurai Hironobu Naiki Yuji Goto 《Protein science : a publication of the Protein Society》2009,18(8):1592-1601
In patients with dialysis‐related amyloidosis, β2‐microglobulin (β2‐m) is a major structural component of amyloid fibrils. It has been suggested that the partial unfolding of β2‐m is a prerequisite to the formation of amyloid fibrils, and that the folding intermediate trapped by the non‐native trans‐Pro32 isomer leads to the formation of amyloid fibrils. Although clarifying the structure of this refolding intermediate by high resolution NMR spectroscopy is important, this has been made difficult by the limited lifetime of the intermediate. Here, we studied the structure of the refolding intermediate using a combination of amino acid selective labeling with wheat germ cell‐free protein synthesis and NMR techniques. The HSQC spectra of β2‐ms labeled selectively at either phenylalanine, leucine, or valine enabled us to monitor the structures of the refolding intermediate. The results suggested that the refolding intermediate has an overall fold and cores similar to the native structure, but contains disordered structures around Pro32. The fluctuation of the β‐sheet regions especially the last half of the βB strand and the first half of the βE strand, both suggested to be important for amyloidogenicity, may transform β2‐m into an amyloidogenic structure. 相似文献
77.
Shinya Fujii Kiminori Ohta Tokuhito Goto Hiroyuki Kagechika Yasuyuki Endo 《Bioorganic & medicinal chemistry》2009,17(1):344-350
A novel series of androgen receptor (AR) ligands bearing an acidic heterocycle with hydrogen-bonding ability as the terminal polar group was developed. Since most non-steroidal AR ligands so far known are structurally limited to nitro- or cyanobenzanilide as the polar pharmacophore, development of alternative hydrogen-bonding components is required to obtain novel AR ligands. Various acidic heterocycles were introduced into a hydrophobic phenylcarborane (1-phenyl-1,12-dicarba-closo-dodecaborane) core structure to provide a moiety that could interact effectively with the critical basic arginine residue of the AR ligand binding domain. The most potent compounds, 1,2,4-oxadiazole-5-thione derivatives 21a and 21b, exhibited higher affinity for hAR than did the well-known anti-androgen hydroxyflutamide. The results suggest that this heterocyclic functionality is potential bioisoster of the nitro and cyano groups forming the polar pharmacophores of known non-steroidal AR ligands. 相似文献
78.
Susumu Goto Yoshiaki Tsuda Yukihiro Koike Chunlan Lian Yuji Ide 《Ecological Research》2009,24(6):1267-1277
To evaluate the effects of landscape and demographic history on genetic variation in Picea glehnii at a regional scale we have investigated the genetic diversity and genetic differentiation of P. glehnii populations in the Furano region, central Hokkaido, Japan, using seven simple sequence repeat (SSR) markers. We found significant
correlations between elevation and genetic diversity parameters. The value of A
[46] increased and the value of F
IS decreased with increasing elevation, while F
IS values were not significantly different from 0 in any of the populations. Significant recent bottlenecks were detected for
isolated populations at low-elevation sites and for relatively large populations at moderate- and high-elevation sites. Evolutionary
events pre-dating the Holocene should be taken into consideration, as elevational gradients should be with respect to locally
adapted traits such as flowering phenology, However, the palynological data from the Holocene in this region suggest that
the distribution pattern of genetic diversity of P. glehnii detected here may have been influenced by past demographic history related to the elevation shifts in this species’ distribution
associated with climate change during this period. Population differentiation was low, with F
ST and G′ST values of 0.022 and 0.065, respectively. However, genetic boundaries were detected around one swamp population (C13). Therefore,
significant isolation by distance (IBD) was not detected when all populations were considered, but there was significant IBD
when the C13 population was excluded. Information on genetic diversity and genetic differentiation at the regional scale may
be useful for selecting seed sources for afforestation programs for P. glehnii. 相似文献
79.
Takeo Sato Shugo Maekawa Shigetaka Yasuda Yutaka Sonoda Etsuko Katoh Takanari Ichikawa Miki Nakazawa Motoaki Seki Kazuo Shinozaki Minami Matsui Derek B. Goto Akira Ikeda Junji Yamaguchi 《The Plant journal : for cell and molecular biology》2009,60(5):852-864
Plants are able to sense and respond to changes in the balance between carbon (C) and nitrogen (N) metabolite availability, known as the C/N response. During the transition to photoautotrophic growth following germination, growth of seedlings is arrested if a high external C/N ratio is detected. To clarify the mechanisms for C/N sensing and signaling during this transition period, we screened a large collection of FOX transgenic plants, overexpressing full‐length cDNAs, for individuals able to continue post‐germinative growth under severe C/N stress. One line, cni1‐D (carbon/nitrogen insensitive 1‐dominant), was shown to have a suppressed sensitivity to C/N conditions at both the physiological and molecular level. The CNI1 cDNA encoded a predicted RING‐type ubiquitin ligase previously annotated as ATL31. Overexpression of ATL31 was confirmed to be responsible for the cni1‐D phenotype, and a knock‐out of this gene resulted in hypersensitivity to C/N conditions during post‐germinative growth. The ATL31 protein was confirmed to contain ubiquitin ligase activity using an in vitro assay system. Moreover, removal of this ubiquitin ligase activity from the overexpressed protein resulted in the loss of the mutant phenotype. Taken together, these data demonstrated that CNI1/ATL31 activity is required for the plant C/N response during seedling growth transition. 相似文献
80.
The bilayer phase transitions of six kinds of mixed-chain phosphatidylcholines (PCs) with an unsaturated acyl chain in the sn-1 or sn-2 position, 1-oleoyl-2-stearoyl- (OSPC), 1-stearoyl-2-oleoyl- (SOPC), 1-oleoyl-2-palmitoyl- (OPPC), 1-palmitoyl-2-oleoyl- (POPC), 1-oleoyl-2-myristoyl- (OMPC) and 1-myristoyl-2-oleoyl-sn-glycero-3-phosphocholine (MOPC), were observed by means of differential scanning calorimetry (DSC) and high-pressure light transmittance measurements. Bilayer membranes of SOPC, POPC and MOPC with an unsaturated acyl chain in the sn-2 position exhibited only one phase transition, which was identified as the main transition between the lamellar gel (Lβ) and liquid crystalline (Lα) phases. On the other hand, the bilayer membranes of OSPC, OPPC and OMPC with an unsaturated acyl chain in the sn-1 position exhibited not only the main transition but also a transition from the lamellar crystal (Lc) to the Lβ (or Lα) phase. The stability of their gel phases was markedly affected by pressure and chain length of the saturated acyl chain in the sn-2 position. Considering the effective chain lengths of unsaturated mixed-chain PCs, the difference in the effective chain length between the sn-1 and sn-2 acyl chains was proven to be closely related to the temperature difference of the main transition. That is, a mismatch of the effective chain length promotes a temperature difference of the main transition between the positional isomers. Anomalously small volume changes of the Lc/Lα transition for the OPPC and OMPC bilayers were found despite their large enthalpy changes. This behavior is attributable to the existence of a cis double bond and to significant inequivalence between the sn-1 and sn-2 acyl chains, which brings about a small volume change for chain melting due to loose chain packing, corresponding to a large partial molar volume, even in the Lc phase. Further, the bilayer behavior of unsaturated mixed-chain PCs containing an unsaturated acyl chain in the sn-1 or sn-2 position was well explained by the chemical-potential diagram of a lipid in each phase. 相似文献